generation-aware playback statuses

internal/playback/status_store_test.go

@@ -106,3 +106,50 @@ func TestStatusStoreConcurrentAccess(t *testing.T) {
 		}
 	}
 }
+
+func TestStatusStoreNewGenerationClearsPreviousUnits(t *testing.T) {
+	store := NewStatusStore()
+	store.Observe(Status{Unit: UnitVideo, State: StatePlaying, Generation: 1})
+	store.Observe(Status{Unit: UnitAudio, State: StatePlaying, Generation: 1})
+	want := Status{Unit: UnitSync, State: StateConnecting, Generation: 2}
+	store.Observe(want)
+
+	if _, ok := store.Snapshot(UnitVideo); ok {
+		t.Fatal("video status survived generation change")
+	}
+	if _, ok := store.Snapshot(UnitAudio); ok {
+		t.Fatal("audio status survived generation change")
+	}
+	if got, ok := store.Snapshot(UnitSync); !ok || got != want {
+		t.Fatalf("sync Snapshot() = %#v, %t; want %#v, true", got, ok, want)
+	}
+}
+
+func TestStatusStoreIgnoresOlderGeneration(t *testing.T) {
+	store := NewStatusStore()
+	want := Status{Unit: UnitSync, State: StatePlaying, Generation: 3}
+	store.Observe(want)
+	store.Observe(Status{Unit: UnitVideo, State: StateIdle, Generation: 2})
+
+	if _, ok := store.Snapshot(UnitVideo); ok {
+		t.Fatal("older video status was stored")
+	}
+	if got, ok := store.Snapshot(UnitSync); !ok || got != want {
+		t.Fatalf("sync Snapshot() = %#v, %t; want %#v, true", got, ok, want)
+	}
+}
+
+func TestStatusStoreKeepsEqualGenerationUnitsIndependent(t *testing.T) {
+	store := NewStatusStore()
+	wantVideo := Status{Unit: UnitVideo, State: StatePlaying, Generation: 4}
+	wantAudio := Status{Unit: UnitAudio, State: StateReconnecting, Generation: 4}
+	store.Observe(wantVideo)
+	store.Observe(wantAudio)
+
+	if got, ok := store.Snapshot(UnitVideo); !ok || got != wantVideo {
+		t.Fatalf("video Snapshot() = %#v, %t", got, ok)
+	}
+	if got, ok := store.Snapshot(UnitAudio); !ok || got != wantAudio {
+		t.Fatalf("audio Snapshot() = %#v, %t", got, ok)
+	}
+}